Palestinian Authority officials expressed concern that Tuesday's West Bank shooting attack that
left four Israelis dead would compromise the Palestinian position in upcoming negotiations with
Israel.

Meanwhile, Assistant Secretary of State Phillip Crowley said the US was aware that "external events" could have an impact on the Washington peace summit.

"We also are cognizant that there may well be actors in the region who are deliberately making these kinds of attacks in order to try to sabotage the process," he said.

A Palestinian security source told Ynet that the PA has made great efforts over the last three years to maintain order in the West Bank. He stressed that Israeli officials were aware of the Palestinian forces' effective work, which is coordination with Israel.

"This is by no means a failure on the part of Palestinian side but a serious malfunction. An investigation must be launched to prevent such incidents from accruing again," he said.

According to the source, Palestinian security forces have launched an investigation into the attack based on information received by Israel. the PA estimate that Hamas was
behind the terror attack. Officials said the Hebron area is considered one of the last West Bank enclaves wehre Hamas cells continue to operate.

Recently, Hamas leaders including Politburo Chief Khaled Mashaal called for the resumption of terrorist attack in the West Bank towards the resumption of direct talks.

Last week, Ynet reported that PA security forces arrested Palestinians
who contacted Hezbollah in an attempt to establish cells affiliated with the Lebanese group in the West Bank. According to reports, Kais Obeid, an ex-Israeli-Arab who was involved in kidnapping Elhanan Tannenbaum was responsible for recruiting militants.